Mystra, goddess of magic

Mystra was born from the heart of Ordona a Goddess so powerful that she created the world as it's known. Mystra gained the power of her mother's heart giving her the ability to control all magic and write its laws. Mystra was a pillar in the community of the gods giving guidance on how magic should be used. She was convinced to give the mortals the power of magic by her fellow gods and for a long time, the mortals used it for good. this was called the divergence in 1290bv (bv before the vail)
but when you give power to something as selfish as mankind things get to a stage of evil that not even the gods could have suspected. The mortals twisted the magic and in doing so got the attention of the dreamer and the old ones. The eldritch abominations started to pull on the threads of mankind convincing them to do unspeakable things. The old ones roamed the lands sewing darkness and horror into mortals as a way to feed off the chaos.
The gods wared with these eldritch beings to no success as the horrors seemed to have a good way of hiding themselves or recreating their bodies from nothing. after a long war, the gods got together and created a way to seal these horrors. if they could not be killed surely they could be modified or trapped someplace else. but before their plan could come to fruition the mortals cast a powerful spell pulling Mystra into a cage of their own creation.
Mystra found herself captured in a glass dome her celestial form unable to brake through as her power was sapped from her by the mortals. They used so much of her power that the goddess started to die from rotting and falling apart. the man responsible for this was named Fabian a drow man who strived to become a god himself. however, some of Fabian's followers had seen Mystras torment and freed her from her captivity. letting the goddess of magic re-ascend to her rightful place where she finally knew what she had to do to stop the horrors and man.
Mystra led a charge to create a spell that would ascend the gods to another realm but protect the mortal one. A veil would be created between their realms trapping any devine or horror outside of it. thou this did not stop their influences from getting through the veil but did keep them out. now the gods and horrors watch from afar pulling threads from the heavens instead of the lands. another side effect of this Viel that Mystra did not tell the gods off was that it would take a portion of the mortal's magic with it leaving them with a limit to the use of magic.